For example, in digital video cameras, light from object is converged by lens onto the light receiving surface of photo-electric conversion device such as CCD (Charge Coupled Device), etc., at which photo-electric conversion is carried out so that picture data which is electric signal is provided.
In digital video cameras, light from lens is incident upon CCD through shutter which controls exposure. Accordingly, when shutter speed is low, i.e., exposure time is long, many electric charges are charged in CCD, resulting in the so-called over exposure. Further, picture image obtained at the time of over exposure results in the so-called white overexposure picture image. On the other hand, when exposure time is short, quantity of electric charges charged in CCD becomes lesser. As a result, the so-called under exposure takes place, and picture image obtained results in black underexposure picture image. In order to prevent such white overexposure or black underexposure, it is necessary to set exposure time so that the area from the portion where picture image is the most bright up to the portion where it is the most dark has suitable brightness.
Meanwhile, in conventional digital video cameras, photographing is carried out at the same exposure time with respect to the entirety of the light receiving surface of CCD. Accordingly, in the case where object of high contrast is photographed (imaged), the bright portion results in white overexposure portion, or the dark portion results in black underexposure portion, resulting in the problem that detail of object is lost in the picture image thus obtained.
It is to be noted that while camera with liquid crystal shutter is disclosed in, e.g., the Japanese Patent Application No. 28796/1994, this camera cannot control exposure in pixel units of CCD, but can only set the same exposure time with respect to the entirety of the light receiving surface of CCD.